Recommended Beginners Books

Advertisements

How Many Times Can Light Travel Around the Earth in 1 Second?

If you were traveling at the speed of light you could fly around the world 7 and a half times in one second. Superman eat your heart out.

That is an incredible speed that blows the mind and really
helps the brain to visualise the speed. Is it true? Let’s find out. We’ll need
to know the circumference of planet Earth and how far light travels in a
second.

Let’s start with the easy bit. The distance light would
travel in a second.

The Distance Light Travels in 1 Second

The speed of light is 670,616,629 miles per hour. That is a
pretty large number to comprehend. So if we divide this by 3600, which is the
number of seconds in an hour the distance light travels in a second is 186,282
miles.

What is the circumference of the Earth?

Now it gets a bit tricky because the Earth has two different
circumferences, but does it matter which one we choose. Let’s take a look.

Earth is a ball of rock, metal and water with a huge mass.
As the Earth is spinning this rock and water is displaced by forces that cause
the Earth to flatten out. The result of the spinning is that the circumference
at the equator is longer than the circumference of Earth if you went from pole
to pole. This is known as the meridional
circumference. The circumference around the equator is 24, 901 miles and around
the poles it is 24, 860 mile, difference of 41 miles. This means you would need
to drive 41 miles further in your car if you chose to travel around the world
at the equator compared to going around the poles.

Conclusion

If we divide the distance travelled by light by the circumferences
of Earth we find that light travels around the Earth 7.48 times if it goes
around the equator and 7.49 times if it travelled around the poles. Pretty
close and really helps to visualise the pure awesomeness of the speed of light.